The objectives of the ongoing study are to investigate the interaction of some important airborne environmental pollutants with the metabolism of foreign compounds by the liver and lung in several species of animals. Studies are currently being conducted on carbon monoxide and atmospheres with a lowered ambient pO2. Exposure is via inhalation and the effects are being studied in vivo and in vitro. Of high priority are effects on the metabolism of foreign compounds via cyt. P-450 mixed function oxidases. The effects of carbon monoxide exposure will be compared with the effects of exposure to a lowered ambient pO2 sufficient to produce an equivalent degree of hypoxia. The development of a model system showing the interaction of inhaled carbon monoxide with the metabolism of foreign compounds lends itself to a variety of physiologic conditions from which it can be studied. It is planned to study the effects of CO exposure on animals which have cytochrome P-450 levels elevated by other environmental pollutants, on the development of the cytochrome P-450 metabolizing system in normal newborn animals exposed during the immediate post natal period to CO. BIBLIOGRAPHIC REFERENCE: Hitchcock, M. and Krevsky, B. Effect of carbon monoxide on the in-vivo metabolism of zoxazolamine in normal and polycyclic hydrocarbon induced rats and mice. Toxicol. and Appl. Pharmacol. 37: 110-111, 1976.